6. Close the display and turn the computer upside-down on a flat work surface.NOTE: To avoid damaging the system board, you must remove the main battery before you service thecomputer.7. Remove the main battery.8. Turn the computer top-side up.9. Open the display.10. Press the power button to ground the system board.CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet beforeopening the display.CAUTION: Before touching anything inside your computer, ground yourself by touching an unpainted metalsurface, such as the metal at the back of the computer. While you work, periodically touch an unpainted metalsurface to dissipate static electricity, which could harm internal components.11. Remove any installed ExpressCards or Smart Cards from the appropriate slots.Turning Off Your ComputerCAUTION: To avoid losing data, save and close all open files and exit all open programs before you turn off yourcomputer.1. Shut down the operating system:– In Windows 8:* Using a touch-enabled device:a. Swipe in from the right edge of the screen, opening the Charms menu and select Settings.b. Select the and then select Shut down* Using a mouse:a. Point to upper-right corner of the screen and click Settings.b. Click the and select Shut down.– In Windows 7:1. Click Start .2. Click Shut Down.or1. Click Start .2. Click the arrow in the lower-right corner of the Start menu as shown below, and then click ShutDown..2. Ensure that the computer and all attached devices are turned off. If your computer and attached devices did notautomatically turn off when you shut down your operating system, press and hold the power button for about 4seconds to turn them off.6